Method and apparatus for optical printing

ABSTRACT

A typewriter frame and keyboard of conventional type includes a rotating drum of di-electric material carrying a conductive helical strip with which any one of the keys may be selectively engaged to actuate a light emanating apparatus. A character aperture disc is mounted in axially spaced relation to the drum to transmit light along an angular path of travel to a light sensitive material supported on the drum when one of the keys is actuated.

United States Patent Zakrzewski METHOD AND APPARATUS FOR OPTICAL PRINTING [72] ,Inventor: Zdzislaw Zakrzewski, 6520 Gladys Ave., El Cerrito, Calif. 94530 [22] Filed; Oct. 6, 1969 [2]] Appl. No.: 871,395

Related U.S. Application Data [63] Substitute for Ser. No. 484,576, Sept. 2, i965, abandoned.

[52] US. Cl ..95/4.S [51] Int. Cl ..B41b 41/08 [58] Field of Search [151 3,657,978 51 Apr. 25, 1972 [56] References Cited UNITED STATES PATENTS 581,815 .5/1897 Eaton ..95/4.5 X 2,475,497 7/1949 Harrold ..95/4.5

Primary Examiner-John M. Horan Attorney-Robert J. Bird [57] ABSTRACT A typewriter frame and keyboard of conventional type includes a rotating drum of di-electric material carrying a conductive helical strip with which any one of the keys may be selectively engaged to actuate a light emanating apparatus. A character aperture disc is mounted in axially spaced relation to the drum to transmit light along an angular path of travel to a light sensitive material supported on the drum when one of the keys is actuated.

2 Claims, 4 Drawing Figures P'A'TEMTEQAPR 25 I972 AUX I LIARY MECHANISM METHOD AND APPARATUS FOR OPTICAL PRINTING This application is a substitute for application Ser. No. 484,576, filed Sept. 2, 1965, now abandoned.

This invention relates to a method and apparatus for producing printed subject matter on the surface. of a sheet of paper or other material and, more particularly, the invention is concerned with a method and means for optically writing subject matter on a suitable medium, for example, a light sensitive medium supported for movement in a frame or carriage of the conventional typewriter class.

As is well known the conventional forms of typewriters now utilized in the art are complex and constructed of a great many intricate operating parts which add to the over-all weight, size and cost of manufacture and maintenance. There is thus created a need for a means of producing printed characters on a sheet of material utilizing simplified techniques and reduced operating parts.

It is a chief object of the invention, therefore, to deal with this general need for a simplified type of apparatus and to provide an improved technique and typing apparatus for printing subject matter on a sheet of paper or other materials.

Another object of the invention is to devise an optical typewriter apparatus for optically reproducing on a suitable material printing characters which are reproduced by means ofa light scanning device.

Still another object of the invention is to devise a novel arrangement of parts by means of which a standard typewriter keyboard may be combined with a special light exposing apparatus to selectively form printed characters on a light sensitive surface.

Still a further object of the invention is to construct an optical typewriter which will be characterized by relatively high speed of operation, a fewer number of moving parts and other modifications to provide reduced costs of manufacture, operation and maintenance.

The general nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of one preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings in which:

FIG. 1 is a fragmentary elevational view of one preferred form of optical typewi'iter of the invention;

FIG. 2 is a fragmentary perspective view of a portion of the typewriter shown in FIG. 1;

FIG. 3 is a detail elevational view of contact bar means of the invention; and

FIG. 4 is a diagrammatic view illustrating electrical wiring and connected components employed in carrying out the optical typewriter method of the invention.

The principal parts of the apparatus employed in the preferred embodiment of the invention disclosed includes a typewriter frame and a keyboard of somewhat the usual type;

a pulsing light source associated with the frame; and means responsive to movement of any one of the keys in the said keyboard for controlling the projection of light from the pulsing light source onto a suitable medium, for example, a light sensitive surface to form letters or characters in a predetermined manner.

Considering these parts in greater detail, numeral 2 denotes the frame of my optical typewriter in which are supported typewriter keys K representing the letters of the alphabet and/or other commonly used typewriter characters. At the upper side of the frame 2 is mounted a roller 4 and a movable carriage therefor. The roller 4 is adapted to support a sheet 6 of light sensitive paper or other material and to move this material axially of itself along the frame through successive positions when'the spacer bar 8 is repeatedly depressed. The spacer bar 8 may be of the type commonly used on conventional typewriters and may be connected to, the carriage by conventional linkage means.

The sheet material 6 may be set to receive a line of typewritten characters and to be advanced across the machine as the characters are formed and being also capable of rotation to position the sheet material for successive new lines of characan operator key and ters. It should be understood that this specific movement of the light sensitive material is not disclosed in a limiting sense and other arrangements may be resorted to for producing relative movement by a controlled beam of light and a light sensitive sheet material which receives the beam of light.

In accordance with the invention, I provide as noted above, an optical character forming apparatus which may be constructed as an integral part of the typewriter structure above disclosed. An important component of this apparatus is a rotating trigger drum 10 which is mounted in the frame in front of the keyboard K and which is driven by a motor 12 indicated diagrammatically at the left hand side of the frame 2 as viewed in FIGS. 1 and 4. The drum is spring-loaded at one end and at its other end is received against rolls 36 and 34 of a shift mechanism 24. This permits the drum to be shifted axially a predetermined distance when so desired by means of the shift lever mechanism.

The trigger drum 10 is also shown removed from the frame 2 in FIG. 2 and as will be observed from an inspection of this v figure the drum is formed of a nonconductive material provided at its outer peripheral surface with a conducting strip 14. The strip 14 is formed of an electrically conductive material such as copper, aluminum, or some special conducting alloy which extends completely around the drum from end to end in a helical path which just completes one circumference of the drum.

Mounted in the frame 2 in close proximity to the conducting strip 14 is a multiple contact member 16 which is formed with a plurality of contact fingers as 16a. This contact member 16 is secured in the machine frame with the fingers 16a in a horizontally disposed position at the underside of the drum 10 as shown in FIG. 3. The extremities of the contact member 16 are arranged to project immediately above a plurality of lever ends as 18 which form a part of respective keys K. Each row of lever ends 18, corresponding to the respective keys K, are pivotally mounted on a pivot shaft P also supported in the frame in some convenient manner. When a key K is depressed, a lever end 18 is caused to move into contact with a respective contact finger 16a, and moves the finger into contact with the surface of the trigger drum 10. Each finger also functions as a return spring for its respective lever and key.

Fixed to the end of drum 10 is a character disc 20 which is formed around its outer circumferential edge with a series of light apertures formed in the shape of typewriter characters of the class and number commonly employed in typewriters generally. Mounted adjacent the drum 10 is a light source 22 which can be periodically energized to provide a pulsing beam of light employing electrical circuit means such as is illustrated diagrammatically in FIG. 4. Also in contact with the drum is a shift lever 24 which is operable by a shift key 26 mounted in the frame 2 in a manner such that depressing the shift key 26 in a vertical direction results in an axially directed shift of the trigger drum 10 through a predetermined distance.

Supported at an opposite side of the character disc 20 is a projection lens 28, together with a fixed mirror 30 arranged at 45 to the optical axis. Light from the pulsing light source passes through a selected aperture of the character disc and is focussed by the projection lens 28 on mirror 30 and then reflected onto the surface of the light sensitive material 6 to form an image 32 as suggested in FIG. 2. It will be understood that the light sensitive material 6 may be housed or covered by some suitable means to prevent undesirable exposure.

Referring to FIG. 4, the device has one standard connection to be plugged into commercial power supply of volts approximately. It provides power for both electric motor 12 and the power transformer T. Motor 12 is a fractional horsepower motor and serves only to rotate the trigger drum 10 at a constant speed as desired. The transformer is of suitable size to step down the power supply to the level required by safety of the operator and the need of the light source 22, and other mechanisms if any, as broadly described by the term auxiliary mechanism" in FIG. 4.

small supply and the switch S1 set to on position, the motor 12 rotates the trigger drum l and the primary coil of the transformer is energized.

When any one of the keys K is depressed the corresponding contact finger 16a touches the rotating trigger drum 10. At the moment the conducting strip 14 passes over that contact finger which touches the trigger drum surface, a contact is established and the circuit 16a, 16, 14, 22 etc. is closed. The light source 22 is thus energized and emits a pulse of light which passes through the appropriate symbol in the character disc 20.

Suitable electrical or mechanical interlock will prevent repetitive exposure of the same symbol if a key is kept in depressed position longer than time required for one complete revolution of the trigger drum; thus only one character imprint is possible per each separate key activation.

The flashing light source isonly one possible way of utilizing the described circuit. It is possible to achieve the same objective by operating a shutter of any type in the path of the light beam at any point prior to its impact onto the receiving medium. The shutter would allow the light to pass only at the moment the above described circuit is closed.

An important feature of the invention is the novel synchronization of the typewriter operation with the rotative movement of the disc 20 whereby a pulsing light beam passed through a character aperture in the character disc will always be snychronized with the corresponding character of a key member which is depressed by an operator using the machine.

It will be observed that the conducting strip 14, as noted above, extends helically through the full length of the drum as well as its circumference without overlapping. Since the lever ends 18 and adjacent contact fingers 16a are located in spaced apart positions such that each contact finger may be moved into contact with the conducting strip 14 at different points therealong, it necessarily obtains that each typewriter key K has a definite reference point of its own on the drum.

it will be appreciated that the drum may be driven by a motor 12 ata constant speed of, for example, 600 or more r.p.m. Therefore, the helical conducting strip passes through the points of contact with the individual fingers in a precise constant sequence. Thus there is realized a repetitive triggering mechanism by means of which selected electrical energizing of the pulsing light source may be accomplished in accordance with any desired sequence of typewriter key operatlon.

It will be further observed that by rigidly mounting the character disc 20 on one end of the trigger drum 10 as disclosed, I may align the character aperture with the light source in a predetermined relationship such that energizing the light source by depressing a key will provide for projecting a light image through an aperture corresponding to the marking of the key to thereby obtain exposure of the desired character on the light sensitive material 6. Thus there is established a reliable condition for repetitive synchronization. I

It will be noted that each key K can be used to form either one of two characters. For example, in'FlG. 2 there is shown a a" and beside it a capital "A" on the character disc. To shift from one to the other the shift lever 24, earlier described, is operated by depressing shift key 26 which moves the drum axially a predetermined distance. This axial movement of the drum necessarily changes the reference point of any key relative to the helical strip and thus provides for selectively forming either a small a" or a capital A as desired.

I may also desire to modify the mechanism in various ways For example, I may use any number of commercially available methods to obtain the visible image from the focused light input such as electrostatic sensitizing, developing and fixing of image receiving material. I may also use material precoated with light sensitive coating develo ped and fixed b heat, contact with chemically saturated we sponge, suitab e vapors or the like. It will be understood that the particular method chosen may require additional changes in connection with the carriage and other frame parts without in any way affecting the basic mechanism of image forming, selection and transfer, or the general concept of the optical typewriter described above.

It will be understood that the invention may be practiced utilizing various well-known features and devices employed in conventional typewriters including back-up buttons, rapid carriage return lever, margin and intermediary space setting, end of line signal, etc.

I may also use various devices for preventing multiple exposure of the same character by one operation of a key. This may i be done, for example, by limiting the duration of the circuit which controls the operation of the pulsing light beam. Control in this way may be accomplished not only by electronic circuitry, but also by pneumatic circuitry and various other instrumentalities.

It will be understood that various other changes and modifications may be resorted to within the scope of the appended claims.

What is claimed is:

l. A typewriting apparatus including:

a frame,

a carriage to position and advance a character-receiving material relative to said frame,

a keyboard having a plurality of keys, each such key being mounted on a linkage relative to said frame,

a rotatable drum having a continuous helical electrical contact element extending 360 therearound in axial registry with said keyboard,

a stationary conductor bar,

an electric circuit including a source of electric current, a light source, said conductor bar, and said helical contact element, said circuit being normally open between said helical element and said conductor bar,

said linkages being operatively disposed relative to said conductor bar and to said helical element to effect electrical contact therebetween when a key is depressed,

an apertured plate operatively connected to said drum and rotatable therewith, said plate disposed relative to said light source and to said character-receiving material such that when said light source is energized, an image ofanaperture in said plate is transmitted to said characterreceiving material, the apertures in said apertured plate defining outlines of type characters, said apertures being disposed on said plate circumferentially relative to its axis so that individual characters are positioned in the path of said light source simultaneously as their corresponding key linkages are disposed in operative relationship to said helical contact element, and further including shift means to alter the synchronism between key action and light energization so as to enable a single key to effect the printing of more than one character. 2. A typewriting apparatus as defined in claim 1 in which said shift means includes a mechanism to displace said drum in an axial direction relative to said frame and keyboard.

* k t i 

1. A typewriting apparatus including: a frame, a carriage to position and advance a character-receiving material relative to said frame, a keyboard having a plurality of keys, each such key being mounted on a linkage relative to said frame, a rotatable drum having a continuous helical electrical contact element extending 360* therearound in axial registry with said keyboard, a stationary conductor bar, an electric circuit including a source of electric current, a light source, said conductor bar, and said helical contact element, said circuit being normally open between said helical element and said conductor bar, said linkages being operatively disposed relative to said conductor bar and to said helical element to effect electrical contact therebetween when a key is depressed, an apertured plate operatively connected to said drum and rotatable therewith, said plate disposed relative to said light source and to said character-receiving material such that when said light source is energized, an image of an aperture in said plate is transmitted to said character-receiving material, the apertures in said apertured plate defining oUtlines of type characters, said apertures being disposed on said plate circumferentially relative to its axis so that individual characters are positioned in the path of said light source simultaneously as their corresponding key linkages are disposed in operative relationship to said helical contact element, and further including shift means to alter the synchronism between key action and light energization so as to enable a single key to effect the printing of more than one character.
 2. A typewriting apparatus as defined in claim 1 in which said shift means includes a mechanism to displace said drum in an axial direction relative to said frame and keyboard. 